Orbiton-mediated multiphonon scattering in La 1 − x Sr x Mn O 3

We report on Raman scattering measurements of single crystalline ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}\mathrm{Mn}{\mathrm{O}}_{3}$ ($x=0$, 0.06, 0.09, and 0.125), focusing on the high-frequency regime. We observe multiphonon scattering processes up to fourth order which show distinct features: (i) anomalies in peak energy and its relative intensity and (ii) a pronounced temperature, polarization, and doping dependence. These features suggest a mixed orbiton-phonon nature of the observed multiphonon Raman spectra.